Aircraft seats have specific performance requirements that generally relate to weight and crash loads, typically requiring low weight and high strength. These performance requirements are often significant drivers of seat design, especially in seats including integral occupant restraints.
The performance requirements are not always aligned with seat comfort. For instance, to attempt to accommodate occupant comfort, current aircraft seats are able to recline by changing the angle of the seat back. In such a traditional aircraft seat, as the seat back is reclined, increasing frictional force is required under the occupant's backside to keep the occupant from sliding out of the seat. This friction uncomfortably tugs on clothing, can lead to the occupant sliding forward, and may create a gap in the lumbar region of the back or spine. Moreover, current seats that incorporate back/bottom motion do not provide proper back motion relative to the seat bottom—in particular where width is restricted and an actual pivot point cannot be placed at the actual hip point of the seated occupant. Moreover, typical recline mechanisms for seat backs do not approximate recline about the hip point, resulting in either gaps that open up between the back and bottom, up/down shear motion relative to the occupant's back, or both. Further, relatively large recline angles in addition to the natural motion are not possible in current aircraft seating products even with traditional/simple recline geometries.
Another typical concern with aircraft seats, and specifically flight deck seats, is the ability of the pilot to fully extend his or her legs to fully actuate the rudder pedals of the aircraft. In current aircraft seats, this need is addressed through complicated mechanisms that “give-way” under load. These systems, unfortunately, are often poorly designed from an ergonomic perspective and are not well-understood by users, causing misuse and reduced comfort.
The foregoing concerns with traditional flight deck seating lead to back fatigue, discomfort, loss of concentration, and the possibility of injury.